The present invention relates to a wheel drum structure of an inner stator portion with an inbuilt driving control circuit and, more particularly, to a wheel drum type outer rotor motor having an inner stator portion, which uses an inner ring portion thereof to build a maximal hollow space to receive a driving control circuit therein.
As shown in FIG. 1A, a prior art wheel drum type outer rotor motor comprises an axial through inner hole 315, coil wire heads/tails 419, a magnet iron yoke ring 611, an outer rotor housing 612, a housing end cover plate 613, a bearing 614, an outer rotor magnet 615, an inner stator 71, and a sensing circuit board 712.
The bottleneck of manufacturing a motor of high operational efficiency usually arises in the problem of winding an exciting coil, e.g., a winding path 713 of a winding guide needle shown in FIGS. 1B and 1C. For a motor to have a high operational efficiency, it must have corresponding electric load and magnetic load. The electric load relates to the thickness of wound conductor of an exciting coil of a stator. A higher electric load represents a higher exciting current. To have a higher exciting current, an exciting coil with a thicker wound conductor is required so that the higher exciting current can flow therein. To enhance the effective operational efficiency of a motor, the occupied ratio of volume of an exciting coil in a wire groove must be increased to receive stator coils of thicker wire and lower impedance, e.g., stator coils 413 shown in FIGS. 2B and 2C.
Additionally, a driving control circuit of a conventional wheel drum type motor is installed outside the motor. Because a guide wire connected between the driving control circuit or a detecting circuit and the motor is longer, the whole control system is easily affected. Moreover, the installed position of the driving control circuit is also a problem. If the driving control circuit is used in an electric light vehicle, the path of the guide wire between the wheel drum type motor and the driving control circuit and delicacy of the whole system must be taken into account.
In consideration of the problems of a conventional wheel drum type motor, the inner bore of a conventional inner stator portion (e.g., an inner stator 71 shown in FIG. 1B) is maximally enlarged (e.g., a hollow space 213 shown in FIG. 2B). Because it is alright that magnetic conduction space at the inner bore portion is appropriate when a motor is excited, the inner bore of a stator inner ring portion can be enlarged. The enlarged hollow space can receive a driving control circuit of the motor, hence resolving the problems of disposition of the circuit, wiring engineering, and circuit disturbance. Furthermore, a root end of the stator portion can be equiangularly separated from an outer ring portion of the inner stator according to the number of wire grooves. The separated root end must correspond to the outer ring portion of the inner stator to build embedded joining ends penetrating each other. Therefore, an insulated wire groove seat of the stator root end can be formed at the outer stator coil in advance and then insulatedly disposed in a wire groove seat. This represents that the occupied ratio of volume of the stator coil in the stator wire groove can be greatly enhanced (e.g., (xcex82) shown in FIGS. 2B and 2C). A wheel drum structure of an inner stator portion with an inbuilt driving control circuit of the present invention can let a wheel drum type motor have a high operational efficiency, a high structural strength, and the characteristics of easy installation and maneuver and immune to disturbance.
The various objects and advantages of the present invention will be more readily understood from the following detailed description when read in conjunction with the appended drawing, in which: